PHOENIX (AP) — Rookie Corbin Carroll hit a go-ahead, two-run homer in the eighth inning, Merrill Kelly struck out 12 through seven innings before leaving with an injury and the Arizona Diamondbacks beat the Cincinnati Reds 3-2 on Thursday night.

It was the first of an important four-game series between teams in the middle of a six-team battle for the three National League wild-card spots.

The D-backs have won five straight while the Reds had a three-game winning streak snapped. Arizona moved a half-game ahead of the Reds and Giants for the final wild-card position.

The Reds led 2-1 after seven innings, but Lourdes Gurriel Jr. coaxed a leadoff walk before Carroll — an All-Star who has been the catalyst for many big moments this season — followed with his 22nd homer of the season, a line drive shot to right off reliever Alex Young (4-2).

Paul Sewald worked the ninth for his 28th save, and seventh since coming to the D-backs in a trade deadline swap with the Mariners.

The D-backs broke a scoreless tie in the seventh after loading the bases with no outs. Jace Peterson’s RBI single scored Nick Ahmed, but Gabriel Moreno was thrown out at home after some confusion on the basepaths, putting a damper on a potentially big inning. Tommy Pham and Christian Walker followed with flyouts to right that ended the threat.

The Reds rallied in the eighth when Nick Senzel — who was just promoted from the minors and entered the game as a pinch hitter — hit a towering homer off lefty Kyle Nelson that just cleared the left field wall and landed in the D-backs’ bullpen.

Noelvi Marte followed with a one-out walk and then stole second base, scoring on Stephenson’s line drive single off Miguel Castro (6-6), giving Cincinnati a 2-1 lead.

That set the stage for Carroll, who is among the favorites for NL Rookie of the Year. It snapped a 27-game homer drought for Carroll.

Before the late-inning drama, Kelly and Cincinnati left-hander Brandon Williamson matched scoreless innings through six.

Williamson — a promising rookie — gave up six hits and a walk while striking out six. The Reds went to the bullpen in the seventh because Williamson had already thrown 98 pitches.

Kelly was cruising before warming up for the eighth inning, giving up just one hit. The right-hander threw a pitch and then grimaced, walking around the mound for a few seconds before leaving the field with Arizona’s medical staff due to an undisclosed injury.

Losing Kelly for any amount of time would be a huge blow for the D-backs’ playoff hopes. The 34-year-old has a 10-5 record and 2.97 ERA, combining with fellow right-hander Zac Gallen to form a formidable combo at the top of the rotation.

Pham extended his hitting streak to 14 games with a sixth-inning single. The streak is baseball’s longest active run.

TRAINER’S ROOM

Cincinnati first baseman Joey Votto was placed on the 10-day injured list with left shoulder discomfort on Thursday. The six-time All-Star is hitting .200 with 13 homers. Senzel was called up from Triple-A Louisville to take Votto’s place on the roster.

UP NEXT

The series continues Friday night. Reds RHP Hunter Greene (2-5, 4.72 ERA) was set to start against RHP Brandon Pfaadt (0-6, 6.13 ERA).

Diamondbacks 3, Reds 2

Cincinnati						Arizona
	ab	r	h	bi			ab	r	h	bi
Friedl cf	3	0	0	0		K.Marte 2b	4	0	2	0
McLain 2b	4	0	0	0		Bu.Kennedy dh	3	0	0	0
De La Cruz ss	4	0	0	0		Peterson ph-dh	1	0	1	1
Steer lf	3	0	0	0		Pham rf-lf	4	0	1	0
Martini dh	2	0	0	0		Walker 1b	4	0	0	0
Senzel ph-dh	2	1	1	1		Gurriel Jr. lf	3	1	1	0
Encrncn-Strnd 1b	4	0	0	0		Thomas cf	0	0	0	0
N.Marte 3b	2	1	1	0		Longoria 3b	3	0	0	0
Benson rf	3	0	0	0		Perdomo 3b	0	0	0	0
Stephenson c	3	0	1	1		Carroll cf-rf	4	1	2	2
						Ahmed ss	3	1	0	0
						Moreno c	4	0	3	0
Totals	30	2	3	2		Totals	33	3	10	3

Cincinnati	000	000	020	—	2
Arizona	000	000	12x	—	3

DP–Cincinnati 1, Arizona 0. LOB–Cincinnati 4, Arizona 9. 2B–N.Marte (2). HR–Senzel (10), Carroll (22). SB–N.Marte (3).

	IP		H	R	ER	BB	SO

Cincinnati
Williamson	6		6	0	0	1	6
Farmer	1		3	1	1	1	0
Young L,4-2 BS,1-4	1		1	2	2	1	0

Arizona
Kelly	7		1	0	0	0	12
Nelson BS,0-4		2-3	1	2	2	1	2
Castro W,6-6		1-3	1	0	0	1	0
Sewald S,7-8	1		0	0	0	1	2

Umpires–Home, CB Bucknor; First, Derek Thomas; Second, Jeff Nelson; Third, Chris Segal.

T–2:46. A–18,827 (48,359).